Optical component

Abstract

An optical member (1) is provided with: a light guide body (2) made of a light-transmitting material; and a light-shielding back cover (3) that covers the entire area of the reflective surface, the light guide body having an incident portion (2a) comprising a plurality of projecting incident prism portions (21), a reflective surface (2d) adjacent to the incident portion, and an exit surface (2c) that reflects a part of incident light that has entered the interior from the incident portion to the reflective surface side by means of total reflection. The light guide body is provided with a plurality of incident prism parts, the incident prism parts are arranged so as to have an incident surface (21a) as a surface on which the outside light is incident on the inside of the light guide body and an adjacent surface (21b) as a surface adjacent to the incident surface, and the back cover (3) is arranged so as to abut the adjacent surface (21b) of a rear prism part (211), which is an incident prism part adjacent to the reflecting surface among the plurality of incident prism parts, and so as to be spaced apart from the reflecting surface. The optical member is capable of suppressing the occurrence of a re-image caused by incident light from the outside of an incident surface while using a light guide made of a light-transmitting material.

Description

Technical Field

[0001] The present disclosure relates to an optical component that uses a light guide that internally reflects a part of the light incident from the incident surface and emits the incident light and its reflected light to the outside from a surface different from the incident surface. Background Art

[0002] Conventionally, such an optical component is used, for example, as a blind spot assist device. It is installed on a light shielding body, allows external scene light from a blind spot area generated by the light shielding body to enter internally, reflects it internally, and emits the external scene light from a surface different from the incident surface of the external scene light, so that the blind spot area can be visually confirmed. As such an optical component, for example, the description in Patent Document 1 can be cited.

[0003] The optical component described in Patent Document 1 is composed of a light-transmissive light guide. A part of the external light incident from the incident surface of the light guide is totally reflected internally and guided, and is emitted to the outside from an emission part different from the incident surface, so that a user on the emission surface side can see the external scene of the blind spot. As a result, it becomes a half mirror-free structure that does not require a half mirror made of a reflective material different from the light guide on the emission part side, and the loss caused by the absorption of external light generated by the light guiding inside the light guide and the brightness deviation due to wavelength are reduced.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2023-028532 Summary of the Invention

[0007] Regarding the optical component described in Patent Document 1, since the light guide is made of a light-transmissive material, when it is installed on another light shielding body, external scene light also enters from a surface other than the incident surface in the light guide and facing the other light shielding body. For this optical component, if the external scene light incident from a surface other than the incident surface in the light guide is emitted from the emission surface, it will be visually recognized as a ghost image by the user.

[0008] Therefore, it is conceivable to form a light shielding film on a surface other than the incident surface and the emission surface of the light guide made of a light-transmissive material. However, since the above optical component has a structure that guides the incident light inside the light guide by total reflection, if a light shielding film is formed, the total reflection condition is no longer satisfied, and the user on the emission surface side cannot visually confirm the external scene of the blind spot.

[0009] In view of the above problems, the present disclosure aims to provide an optical component that uses a light guide made of a light-transmissive material and can suppress the occurrence of double images caused by incident light from outside the incident surface.

[0010] According to one aspect of the present disclosure, an optical component includes a light guide and a light-shielding back cover. The light guide is made of a light-transmissive material and has: an incident portion composed of a plurality of protruding incident prism portions; a reflection surface adjacent to the incident portion; and an emission surface opposed to the incident portion and the reflection surface, which emits a part of the incident light incident from the incident portion to the outside and reflects the other part of the incident light to the reflection surface side by total reflection. The back cover covers the entire area of at least the reflection surface in the light guide. Let the surface of the incident prism portion that allows external scene light to enter the inside of the light guide be the incident surface, let the surface adjacent to the incident surface in the incident prism portion be the adjacent surface, and let the incident prism portion adjacent to the reflection surface among the plurality of incident prism portions be the rear prism portion. The back cover abuts against the adjacent surface of the rear prism portion and is arranged with a gap from the reflection surface.

[0011] The optical component has a structure including a light guide with a mirrorless structure capable of guiding light by total reflection and a back cover that covers the entire area of the reflection surface facing a light-shielding body (not shown) with a gap therebetween. Thus, the optical component can use a light guide with a mirrorless structure and can suppress the occurrence of double images caused by light entering the reflection surface from outside the incident surface of the light guide. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a cross-sectional view showing the optical component of the first embodiment.

[0013] Figure 2 is an exploded perspective view showing the optical component of the first embodiment.

[0014] Figure 3 is an explanatory view regarding light guiding in the optical component of the first embodiment, the occurrence of double images assuming no back cover, and the suppression of double images brought about by the back cover.

[0015] Figure 4 is an enlarged view showing the contact portion between the back cover and the incident prism portion.

[0016] Figure 5 is an exploded perspective view showing the optical component of the second embodiment.

[0017] Figure 6 is from Figure 5 viewed from the VI direction.

[0018] Figure 7 This is a cross-sectional view taken along VII-VII showing the state where the light guide is mounted on the holder. Figure 5

[0019] Figure 8 This is a perspective view showing another shape example of the holder according to the second embodiment.

[0020] Figure 9 This corresponds to Figure 6 This is a side view showing the optical component according to the third embodiment.

[0021] Figure 10 This is an exploded perspective view showing the holder according to the third embodiment.

[0022] Figure 11 This is an exploded perspective view showing the optical component according to the fourth embodiment.

[0023] Figure 12 This is a cross-sectional view taken along XII-XII showing the state where the light guide is mounted on the holder. Figure 11 Detailed Embodiment Modes

[0024] Hereinafter, embodiments of the present disclosure will be described based on the drawings. In addition, between the following embodiments, the same or equivalent parts are given the same reference numerals for description.

[0025] (First Embodiment)

[0026] The optical component 1 according to the first embodiment will be described.

[0027] 〔Basic Structure〕

[0028] The optical component 1 of the present embodiment is used, for example, as a blind spot assist device, and is mounted on a component or obstacle that blocks the user's field of view and creates a blind spot, for visually confirming the scene in the blind spot area by the user. For example, in the case of in-vehicle use, the optical component 1 is mounted on a prescribed light-shielding body such as a pillar of the vehicle on which it is mounted, and guides the external scene light from the area that becomes a blind spot due to the light-shielding body to the user side, so that the user can visually confirm the scene in the blind spot area.

[0029] For example, as Figure 1 shown, the optical component 1 of the present embodiment has a light guide 2 and a back cover 3, which are mounted on a light-shielding body (not shown) and are used in a state where the back cover 3 faces the light-shielding body. The optical component 1 has the following structure: by guiding the external scene light inside the light guide 2 and emitting it to the user side, the blind spot area can be visually confirmed, and the back cover 3 prevents unnecessary light from entering the light guide 2.

[0030] For example, as​​Figure 1 As shown, the light guide 2 is a component having an incident portion 2a, a reflecting surface 2d adjacent to the incident portion 2a, an emitting surface 2c facing the incident portion 2a and the reflecting surface 2d, a side surface 2b connecting the incident portion 2a and the emitting surface 2c, and an end surface 2e connecting the emitting surface 2c and the reflecting surface 2d. For example, as Figure 2 shown, the light guide 2 has an upper surface 2f and a lower surface 2g that connect the incident portion 2a, the side surface 2b, the emitting surface 2c, the reflecting surface 2d, and the end surface 2e and face each other. The light guide 2 is, for example, a transparent component that is a single component made of a light-transmissive material. As the light-transmissive material, for example, resin materials such as polyethylene terephthalate, polycarbonate, polyethylene, and acrylic, or inorganic materials such as glass can be used. The light guide 2 has a mirrorless structure that does not have a reflector made of a reflective material different from the light-transmissive material, and is designed to guide incident light from the incident portion 2a by total internal reflection inside. Since the light guide 2 has many common parts with the structure described in Patent Document 1, the characteristic parts will be mainly described in this specification.

[0031] For example, as Figure 1 shown, the incident portion 2a is formed by repeatedly and continuously arranging a plurality of incident prism portions 21 that are triangular protrusions in a plan view in such a way that the extending directions are the same. For example, as Figure 3 shown, one surface of the outer surfaces of the plurality of incident prism portions 21 on the side opposite to the reflecting surface 2d becomes an incident surface 21a for allowing a part of the external scene light L1 to enter the interior, and the reflecting surface 2d is adjacent to the incident portion 2a. The plurality of incident prism portions 21 are arranged, for example, such that the heights of the portions protruding from the reflecting surface 2d are substantially the same and their respective incident surfaces 21a are substantially parallel. Substantially the same means not only the case of being exactly the same, but also the case of being substantially the same including inevitable errors such as processing errors and not being exactly the same. The surface of the outer surfaces of the plurality of incident prism portions 21 on the reflecting surface 2d side becomes an adjacent surface 21b. The inclination angle of the adjacent surface 21b is specified to be below a certain value so as not to hinder the incidence of the external scene light L1 on the incident surface 21a of the adjacent other incident prism portions 21.

[0032] Hereinafter, for the sake of convenience of explanation, as Figure 3 shown, the light that enters the interior from the incident portion 2a among the external scene light L1 from the incident portion 2a and the reflecting surface 2d side is referred to as "incident light L2", and the light that is emitted to the outside from a later-described emission prism portion 22 among the incident light L2 is referred to as "emitted light L3". In addition, in Figure 2 , in order to easily understand the structure of the optical component 1, a part of the outer contour of the later-described light guide 2 and the back cover 3 that cannot be seen from the Figure 2 angle is indicated by a dotted line.

[0033] For example, in order to prevent the incident light L2 from exiting from the side surface 2b to the outside, let the incident angle of the incident light L2 incident on the flat portion 23 be φ, and the inclination of the surface of the side surface 2b be equal to or greater than the incident angle φ. In addition, the incident angle φ of the incident light L2 is the angle formed by the normal direction (hereinafter simply referred to as the "normal direction") of the plane formed by the flat portion 23 or the reflecting surface 2d and the traveling direction of the incident light L2. Regarding the light guide 2, let the refractive index of the material constituting it be n, and let the external medium be air (refractive index = 1). By satisfying the total reflection condition of the following formula (1), light guiding in the mirrorless structure can be performed.

[0034] sinφ≥1 / n…(1)

[0035] The light exit surface 2c has, for example: a plurality of light exit prism portions 22 that are triangular protrusions in a cross-section; and a plurality of flat portions 23 that are adjacent to the light exit prism portions 22 and are planes substantially parallel to the reflecting surface 2d. The light exit surface 2c is the surface where the incident light L2 from the incident portion 2a first arrives, and is a surface formed by alternately arranging the light exit prism portions 22 and the flat portions 23 repeatedly. The plurality of light exit prism portions 22 have a light exit portion 22a that is a surface for emitting the incident light L2 to the outside, and another surface 22b adjacent to the light exit portion 22a, and are, for example, arranged in parallel with the same extending direction. The light exit portion 22a is, for example, parallel to the incident surface 21a. The plurality of flat portions 23 are, for example, flat surfaces located on the same plane, and are the first reflecting surfaces for reflecting the incident light L2 toward the reflecting surface 2d by total reflection.

[0036] Hereinafter, for the sake of convenience of explanation, the direction orthogonal to the extending direction of the light exit prism portion 22 and along the arrangement direction of the plurality of light exit prism portions 22 is referred to as the "first direction D1", and the direction along the above-mentioned normal direction is referred to as the "second direction D2". In addition, the direction along the extending direction of the incident prism portion 21 and the light exit prism portion 22 is referred to as the "third direction D3". The direction from the side surface 2b toward the end surface 2e in the first direction D1 is the direction in which the incident light L2 is guided, and can also be said to be the light guiding direction. The second direction D2 corresponds to the thickness direction of the light guide 2.

[0037] The reflecting surface 2d is the second reflecting surface for reflecting the incident light L2 reflected by the flat portion 23 back toward the light exit surface 2c side by total reflection. In the case where the light exit surface 2c facing the user side is the surface, the reflecting surface 2d is the surface corresponding to the back surface. In order to prevent the external scene light L1 from entering, the entire reflecting surface 2d is covered with a back cover 3 with a gap.

[0038] Here, for example, as in Figure 3As shown by the dotted arrow, for the light guide 2, in the hypothetical case where there is no back cover 3, a part of the outdoor light L1 directly enters the interior from the reflecting surface 2d, and this incident light exits from the emitting surface 2c as an unwanted ghost light L4. If the ghost light L4 reaches the user's eyes together with the emitted light L3, the user will visually recognize not only the scene in the blind area formed by the emitted light L3, but also the scene formed by the ghost light L4. In order to suppress the occurrence of such ghost images and improve the visual recognition of the blind area, the optical component 1 is configured such that the back cover 3 prevents the outdoor light L1 from entering the reflecting surface 2d.

[0039] The end face 2e is the face where a part of the incident light L2 finally arrives. The end face 2e can form a single plane together with the emitting part 22a of the emitting prism part 22, or can be made into other face shapes, and can be of any shape.

[0040] The upper surface 2f and the lower surface 2g, like the side surface 2b, are non-optical surfaces and are not used for guiding or reflecting the incident light L2 inside the light guide 2. The upper surface 2f and the lower surface 2g are, for example, each a single flat surface connecting the incident part 2a, the emitting surface 2c, the reflecting surface 2d, and the end face 2e, and are arranged in parallel, but can also be made into any shape within the range that does not obstruct the guiding of the incident light L2.

[0041] The back cover 3 is a light-shielding component that prevents the outdoor light L1 from entering the reflecting surface 2d. The back cover 3 is, for example, made into a flat plate shape, and can be entirely composed of any light-shielding material such as resin or metal, or can be a structure in which a part or all of the outer surface is coated with black paint or the like. Thus, as long as the back cover 3 is a structure that does not allow light to pass through, the material and structure can be appropriately changed. The back cover 3 is, for example, preferably composed of a black light-shielding component with a visible light absorption rate of a specified value or more.

[0042] The back cover 3 is, for example, preferably a rough surface that is less likely to reflect light compared to a mirror surface on the face facing the reflecting surface 2d. Thus, for example, when external light from the emitting surface 2c enters the light guide 2 and is emitted from the reflecting surface 2d to the back cover 3, the reflection of the emitted light on the surface of the back cover 3 is suppressed, and the visual recognition of the blind area visually recognized by the user from the emitting surface 2c is further improved. In addition, the rough surface described here refers to a surface that has not been subjected to a flattening process such as mirror processing that makes the surface roughness below a specified value.

[0043] For example, as Figure 4As shown, the back cover 3 is composed of a plate member 31 and an elastomer 32 mounted at the end of the plate member 31. The plate member 31 has an arbitrary structure that does not allow light to pass through. Let the rear prism portion 211 be the closest to the reflection surface 2d among the plurality of incident prism portions 21. The back cover 3 is arranged such that the elastomer 32 abuts against the adjacent surface 21b of the rear prism portion 211. The elastomer 32 is a member having light-shielding properties and elasticity, such as black rubber. While preventing damage to the rear prism portion 211 due to contact with the back cover 3, it fills the gap between the rear prism portion 211 and the plate member 31, and functions to prevent light from entering the reflection surface 2d. The back cover 3 is arranged at a gap such that the plate member 31 and the elastomer 32 do not contact the reflection surface 2d, so as not to obstruct the total reflection of the incident light L2 on the reflection surface 2d.

[0044] In addition, if a light-shielding film is formed by applying a black coating to the reflection surface 2d of the light guide body 2, the total reflection condition of the above formula (1) is not satisfied, and the light guiding performance is impaired. Therefore, for the light guide body 2 of the mirrorless structure, the reflection surface 2d cannot be directly processed for light shielding.

[0045] Let the width of the reflection surface 2d of the light guide body 2 in the first direction D1 be Wr1, and the width in the third direction D3 be Wr2. For the back cover 3, the width in the first direction D1 is Wc1 that is not less than Wr1, and the width in the third direction D3 is Wc2 that is not less than Wr2. In other words, the planar size of the back cover 3 is not less than that of the reflection surface 2d to cover the entire area of the reflection surface 2d. Thus, the back cover 3 prevents the external scene light L1 from entering the reflection surface 2d and suppresses the occurrence of double images.

[0046] According to the present embodiment, the optical component 1 includes: a light guide body 2 of a mirrorless structure capable of guiding light based on total reflection; and a back cover 3 that covers the entire area of the reflection surface 2d of the light guide body 2 facing a light-shielding body (not shown) with a gap therebetween. Thus, the optical component 1 uses the light guide body 2 of the mirrorless structure and can suppress the occurrence of double images caused by light other than the incident surface 21a of the light guide body 2. In addition, the optical component 1 can also obtain the following effects.

[0047] (1) The surface of the back cover 3 of the optical component 1 facing the light guide body 2 is a rough surface that is not smoothed. Thus, the surface reflection of light on the surface of the back cover 3 is suppressed, and the unwanted light is reduced from reaching the emission surface 2c. Therefore, the visual recognition of the blind area region on the emission surface 2c side can be further improved.

[0048] (2) The portion of the optical component 1 in the back cover 3 that abuts against the rear prism portion 211 of the light guide 2 is a light-shielding elastic body 32. Thus, damage to the light guide 2 caused by the back cover 3 is prevented, and the gap at the abutting portion between the rear prism portion 211 of the light guide 2 and the back cover 3 is filled, achieving the effect of further suppressing the direct incidence of external scene light L1 onto the reflecting surface 2d.

[0049] (Second Embodiment)

[0050] The optical component 1 of the second embodiment will be described.

[0051] For example, as Figure 5 shown, the difference between the optical component 1 of this embodiment and the above-described first embodiment is that it has a holder 10 for the light guide 2 with the back cover 3 as a part. In this embodiment, mainly this difference will be described.

[0052] In Figure 5 it is the same as Figure 1 that for a part of the portion of the outer contour of the light guide 2 that cannot be seen at the angle shown in Figure 5 , it is indicated by a dashed line, and for a part of the outer contour of the upper cover 4 and the lower cover 5 to be described later, it is also indicated by a dashed line. These are the same in the following Figure 11 . In Figure 6 it is the same as Figure 6 that for the outer contour of the portion of the light guide 2 that overlaps with the holder 10 and the portion of the outer contour of the upper cover 4 to be described later that cannot be seen at the angle shown in Figure 9 , it is indicated by a dashed line. These are the same in the following Figure 7 . In addition,

[0053] For example, as Figure 5 shown, the holder 10 has an upper cover 4 and a lower cover 5 in addition to the back cover 3.

[0054] The upper cover 4 is a component that faces the upper surface 2f of the light guide 2 and holds the upper surface 2f of the light guide 2. For example, on the opposing surface 4a that faces the upper surface 2f of the light guide 2, the upper cover 4 is formed with a groove-shaped recess 41 for holding the light guide 2. For example, as Figure 6As shown, for the upper surface cover 4, a surface adjacent to the opposed surface 4a and on the side of the reflecting surface 2d rather than the light emitting surface 2c of the light guide 2 is defined as the end surface 4b, and the rear surface cover 3 is mounted on the end surface 4b. The width of the upper surface cover 4 in the first direction D1 is larger than the width of the rear surface cover 3 in the same direction, covering the entire area of the upper surface 2f of the light guide 2. The end of the light emitting side surface 4c, which is the surface of the upper surface cover 4 opposite to the end surface 4b, forms a chamfered and curved shape. Thus, the surface of the upper surface cover 4 on the user side becomes a rounded shape without corners, preventing injury to the user.

[0055] The lower surface cover 5 is a component paired with the upper surface cover 4 and is used to hold the light guide 2 together with the upper surface cover 4. The lower surface cover 5, for example, faces the lower surface 2g of the light guide 2, and a groove-shaped recess 51 for holding the light guide 2 is formed on the opposed surface 5a facing the lower surface 2g. The width of the lower surface cover 5 in the first direction D1 is larger than the width of the rear surface cover 3 in the same direction, covering the entire area of the lower surface 2g of the light guide 2. For example, as Figure 7 shown, the lower surface cover 5 has basically the same structure as the upper surface cover 4. The rear surface cover 3 is mounted on the end surface 5b, which is adjacent to the opposed surface 5a and on the side of the reflecting surface 2d rather than the light emitting surface 2c of the light guide 2. For example, for the same reason as the upper surface cover 4, the end of the light emitting side surface 5c, which is the surface opposite to the end surface 5b of the lower surface cover 5, forms a chamfered and curved shape.

[0056] In addition, the rear surface cover 3 can be either integral with the upper surface cover 4 and the lower surface cover 5 or separate. In the latter case, it is mounted on the upper surface cover 4 and the lower surface cover 5 by any method such as a connecting component like a screw (not shown) or an adhesive. Further, the rear surface cover 3 is mounted at a position closer to the end surfaces 4b, 5b than the recesses 41, 51 in the upper surface cover 4 and the lower surface cover 5 to connect the two covers. Thus, the holding body 10 can hold the light guide 2 while ensuring a gap between the reflecting surface 2d of the light guide 2 and the rear surface cover 3. For example, as Figure 8 shown, the rear surface cover 3 can also be mounted not on the end surfaces 4b, 5b of the covers 4, 5 but on the opposed surfaces 4a, 5a at a position closer to the end surfaces 4b, 5b than the recesses 41, 51.

[0057] Preferably, at least the surfaces of the upper surface cover 4 and the lower surface cover 5 facing the light guide 2 are rough surfaces with light-shielding properties. Thus, external light is inhibited from entering the upper surface 2f or the lower surface 2g of the light guide 2 from the side of the upper surface cover 4 and the lower surface cover 5, and surface reflection of light on the opposed surfaces 4a, 5a is inhibited, making it difficult for unwanted light to reach the light emitting surface 2c and further improving the visual recognition in the blind area. Similar to the rear surface cover 3, a part or all of the upper surface cover 4 and the lower surface cover 5 are made of any material with light-shielding properties.

[0058] For example, in the present embodiment, in order to be able to mount the upper surface cover 4 and the lower surface cover 5, as Figure 5 shown, the light guide 2 is configured such that both ends of the incident prism portion 21 and the emission prism portion 22 do not reach the upper surface 2f and the lower surface 2g. Thus, the prism portions 21, 22 of the light guide 2 can be inserted into the recesses 41, 51 of the upper surface cover 4 and the lower surface cover 5 without interference, and can be held by the holding body 10. In addition, the light guide 2 may have any shape as long as it can be mounted on the holding body 10, and may also have a structure with protrusions on the upper surface 2f and the lower surface 2g that match the widths of the recesses 41, 51, or the structure may be appropriately changed within a range that does not obstruct the incident light L2. The same applies to the upper surface cover 4 and the lower surface cover 5 in this regard.

[0059] According to the present embodiment, on the basis of the above-described first embodiment, an optical component 1 is obtained that has a structure in which the position relationship between the light guide 2 and the back cover 3 is maintained and can be fixed to a light-shielding body (not shown). In addition, the optical component 1 can also achieve the following effects.

[0060] (1) The optical component 1 has a structure in which the upper surface cover 4 and the lower surface cover 5 respectively have recesses 41, 51 for holding the light guide 2. Thus, the optical component 1 is held in a state where the light guide 2 is fitted into the recesses 41, 51 of the paired upper surface cover 4 and lower surface cover 5 in the holding body 10.

[0061] (2) The optical component 1 is mounted such that the back cover 3 connects the upper surface cover 4 and the lower surface cover 5 at a position closer to the end face 4b, 5b side than the recesses 41, 51 of the upper surface cover 4 and the lower surface cover 5. Thus, the optical component 1 has a structure in which the light guide 2 is held by the holding body 10 and a gap between the reflection surface 2d of the light guide 2 and the back cover 3 is ensured.

[0062] (3) The surfaces of the upper surface cover 4 and the lower surface cover 5 of the optical component 1 that face the light guide 2 are light-shielding rough surfaces. Thus, the intrusion of external light from the upper surface cover 4 and the lower surface cover 5 sides into the light guide 2 and the surface reflection of light on the surfaces of the two covers on the light guide 2 side are suppressed, further improving the visual recognition of the blind area region brought about by the light guide 2.

[0063] (4) The widths of the upper surface cover 4 and the lower surface cover 5 of the optical component 1 in the first direction D1 corresponding to the light guide direction are larger than those of the back cover 3, covering the entire regions of the upper surface 2f and the lower surface 2g. Thus, the intrusion of unwanted external light into the upper surface 2f and the lower surface 2g of the light guide 2 is prevented, further improving the visual recognition of the blind area region brought about by the light guide 2.

[0064] (5) The end portions of the light-emitting sides 4c and 5c of the upper surface cover 4 and the lower surface cover 5 of the optical component 1 have a curved shape without corners. As a result, the end portions of the part of the holding body 10 facing the user side have a rounded shape without sharp corners, forming a structure that can prevent the user from being injured.

[0065] (Third Embodiment)

[0066] The optical component 1 of the third embodiment will be described.

[0067] For example, as Figure 9 shown, the difference between the optical component 1 of the present embodiment and the above-described second embodiment is that the holding body 10 further has a rear cover 6. In the present embodiment, the differences will mainly be described.

[0068] In Figure 9 , Figure 10 , the parts of the outer contour of the rear cover 6 that cannot be seen at the angle shown in Figure 9 are indicated by dashed lines. In Figure 10 , similar to Figure 2 , the parts of the outer contour of the back cover 3 that cannot be seen are indicated by dashed lines.

[0069] In the present embodiment, in addition to having the back cover 3, the upper surface cover 4, and the lower surface cover 5, the holding body 10 further has a rear cover 6 that covers the end face 2e side of the light guide 2. Assuming that the side face 2b of the light guide 2 is the front and the end face 2e is the rear, in the present embodiment, the holding body 10 covers not only the upper surface 2f and the lower surface 2g of the light guide 2 but also the end face 2e, and the part excluding the back cover 3 has a U-shaped configuration.

[0070] The rear cover 6 is a member that connects the upper surface cover 4 and the lower surface cover 5, covers the end face 2e side of the light guide 2, and holds the light guide 2. For example, on the opposing face 6a of the rear cover 6 that faces the end face 2e of the light guide 2, a groove-shaped recess 61 for holding the light guide 2 is formed. In addition, for example, the recess 61 may have a shape that fits with a part or all of the end face 2e, and its shape, dimensions, etc. can be appropriately changed according to the shape of the end face 2e of the light guide 2. For example, the width of the rear cover 6 in the third direction D3 is larger than the width of the back cover 3 in the same direction, covering the entire area of the end face 2e of the light guide 2. For example, as Figure 10 shown, the rear cover 6 basically has the same structure as the upper surface cover 4 and the lower surface cover 5. For the rear cover 6, the back cover 3 is installed on the end face 6b that is adjacent to the opposing face 6a and is on the reflection face 2d side compared to the light-emitting face 2c of the light guide 2. For example, for the same reason as the upper surface cover 4 and the lower surface cover 5, the end portion of the light-emitting side 6c, which is the opposite face of the end face 6b of the rear cover 6, has a chamfered curved shape.

[0071] In addition, in the present embodiment, the upper surface cover 4 and the lower surface cover 5, for example, the ends of their injection sides 4c and 5c other than the end on the rear cover 6 side are formed into a chamfered curved shape, and the end on the rear cover 6 side is made into a flat surface without a step due to the installation of the rear cover 6.

[0072] The rear cover 6 may be integral with a part or all of the back cover 3, the upper surface cover 4, and the lower surface cover 5, or may be separate. In the latter case, it is installed on the upper surface cover 4 or the like by any method such as a connecting member (not shown) or an adhesive. By having the rear cover 6, the holding body 10 prevents the positional deviation between the upper surface cover 4 and the lower surface cover 5, and becomes a structure capable of more stably holding and fixing the light guide 2. In addition, in the present embodiment, the back cover 3 may be installed on the ribs with the portions on the end face 4b to 6b side compared with the concave portions 41, 51, and 61 in the opposed faces 4a, 5a, and 6a of the covers 4, 5, and 6 as ribs. In addition, for the covers 4, 5, and 6, except for the portions of the ribs facing the incident prism portion 21, if the thickness, that is, the width in the second direction D2 is made larger, the gap between the back cover 3 and the reflection surface 2d of the light guide 2 can be reliably ensured, so it is preferable.

[0073] The rear cover 6 is preferably, for example, a rough surface having light-shielding properties at least on the opposed surface 6a. Thereby, it is possible to suppress the intrusion of undesired external light into the end face 2e via the rear cover 6 and the surface reflection of light on the opposed surface 6a of the rear cover 6, and further improve the visual recognition of the blind area region brought by the light guide 2. Similar to the upper surface cover 4 and the lower surface cover 5, the rear cover 6 may be made of any material having light-shielding properties not only on the opposed surface 6a but also entirely.

[0074] According to the present embodiment, based on the effects of the above-described second embodiment, an optical component 1 having a structure that prevents the positional deviation between the upper surface cover 4 and the lower surface cover 5 and can more stably hold and fix the light guide 2 is obtained. In addition, the optical component 1 can also obtain the following effects.

[0075] (1) At least the surface of the rear cover 6 of the optical component 1 facing the light guide 2 is a rough surface having light-shielding properties. Thereby, it is also possible to obtain the effect of suppressing the intrusion of external light into the end face 2e via the rear cover 6 and the surface reflection of light on the opposed surface 6a, and further improving the visual recognition of the blind area region brought by the light guide 2.

[0076] (2) The rear cover 6 of the optical component 1 has a concave portion 61 for holding the light guide 2 on its opposed surface 6a. Thus, the optical component 1 holds the light guide 2 by the upper surface cover 4, the lower surface cover 5, and the rear cover 6, and becomes a more stable structure for fixing the light guide 2.

[0077] (3) The optical component 1, like the upper surface cover 4 and the lower surface cover 5, is configured to prevent user injury by making the end of the emission side 6c of the rear cover 6 have a curved shape without corners.

[0078] (Fourth Embodiment)

[0079] The optical component 1 of the fourth embodiment will be described.

[0080] For example, as Figure 11 shown, the difference between the optical component 1 of this embodiment and the above-described second embodiment is that ribs 24 are formed near the end of the reflection surface 2d in the light guide 2. In this embodiment, the difference will be mainly described.

[0081] In this embodiment, the light guide 2, for example, has protruding rib-shaped ribs 24 formed near the upper surface 2f and the lower surface 2g in the reflection surface 2d. For example, as Figure 12 shown, two ribs 24 are formed at both ends or near both ends in the third direction D3, on the inner side of the reflection surface 2d in the light guide 2 compared to the part inserted into the recess 41 of the upper surface cover 4 and the recess 51 of the lower surface cover 5. The two ribs 24 are arranged in parallel, extending linearly along the first direction D1, for example. The ribs 24 are parts that prevent the rear cover 3 from contacting the reflection surface 2d of the light guide 2 and hindering the total reflection of the incident light L2 on the reflection surface 2d, even when the rear cover 3 is deformed due to heat or the like.

[0082] In addition, the ribs 24 are, for example, part of the light guide 2 and are formed by a molding method using a mold (not shown), like the prism parts 21 and 22. The ribs 24 only need to be formed at both ends or near both ends in the third direction D3 and can prevent the rear cover 3 from contacting the reflection surface 2d, and their number, shape, etc. can also be appropriately changed.

[0083] According to this embodiment, based on the effects of the above-described second embodiment, an optical component 1 with a structure that can more reliably prevent the rear cover 3 from contacting the reflection surface 2d of the light guide 2 can be obtained.

[0084] (Other Embodiments)

[0085] The present disclosure has been described based on the embodiments, but it should be understood that the present disclosure is not limited to these embodiments or structures. The present disclosure also includes various modifications or variations within an equivalent range. In addition, various combinations or forms, as well as other combinations or forms including only one element of them, including more than or less than one element, also fall within the scope or concept of the present disclosure.

[0086] In addition, in each of the above-described embodiments, the elements constituting the embodiments are not necessarily essential elements, except in cases where they are specifically indicated as being necessary and cases where they are clearly considered to be necessary in principle, etc. Further, in each of the above-described embodiments, when referring to numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment, it is not limited to that specific number, except in cases where it is specifically indicated as being necessary and cases where it is clearly limited to a specific number in principle, etc. Additionally, in each of the above-described embodiments, when referring to the shape, positional relationship, etc. of the constituent elements, etc., it is not limited to that shape, positional relationship, etc., except in cases where it is specifically indicated and cases where it is clearly limited to a specific shape, positional relationship, etc. in principle, etc.

Claims

1. An optical component, comprising a light guide and a light-shielding back cover, wherein the light guide is made of a light-transmissive material and has: an incident portion composed of a plurality of protruding incident prism portions; a reflecting surface adjacent to the incident portion; and an emitting surface facing the incident portion and the reflecting surface, which emits a part of the incident light incident from the incident portion to the outside and reflects the other part of the incident light to the reflecting surface side by total reflection, the back cover covers at least the entire area of the reflecting surface in the light guide, the surface of the incident prism portion that allows external scene light to enter the interior of the light guide is defined as the incident surface, and the surface adjacent to the incident surface is defined as the adjacent surface; the incident prism portion among the plurality of incident prism portions that is adjacent to the reflecting surface is defined as the rear prism portion, the back cover abuts against the adjacent surface of the rear prism portion and is disposed with a gap from the reflecting surface.

2. The optical component according to claim 1, the surface of the back cover facing the reflecting surface is a rough surface.

3. The optical component according to claim 1 or 2, the portion of the back cover that abuts against the rear prism portion is an elastomer with light-shielding properties.

4. The optical component according to claim 1 or 2, the light guide has two surfaces, namely an upper surface and a lower surface, that connect the incident portion, the emitting surface, and the reflecting surface, the back cover forms a part of a holding body that holds the light guide, in addition to the back cover, the holding body further has an upper surface cover and a lower surface cover. The upper surface cover faces the upper surface and holds the upper surface; the lower surface cover faces the lower surface and holds the lower surface.

5. The optical component according to claim 4, the upper surface cover has a concave portion that holds the upper surface of the light guide, the lower surface cover has a concave portion that holds the lower surface of the light guide.

6. The optical component according to claim 5, the surface of the upper surface cover and the lower surface cover that is adjacent to the surface where the concave portion is formed and is closer to the reflecting surface than the emitting surface is defined as the end surface, the back cover is installed at a position closer to the end surface than the concave portion in the upper surface cover and the lower surface cover to connect the upper surface cover and the lower surface cover.

7. The optical component according to claim 4, the surfaces of the upper surface cover and the lower surface cover facing the light guide are light-shielding surfaces and rough surfaces.

8. The optical component according to claim 4, the direction orthogonal to the extending direction of the incident prism portion and along the direction in which the plurality of incident prism portions are arranged is defined as the light guiding direction, the width of the upper surface cover and the lower surface cover in the light guiding direction is greater than the width of the back cover in the light guiding direction.

9. The optical component according to claim 4, let the surface of the light guide that connects the emitting surface, the reflecting surface, the upper surface, and the lower surface be the end surface, The above-mentioned holding body further has a rear cover, which is located on the side of the above-mentioned end face and connects at least the above-mentioned upper surface cover and the above-mentioned lower surface cover.

10. The optical component according to claim 9, The surface of the above-mentioned rear cover facing the above-mentioned light guide is a light-shielding surface and a rough surface.

11. The optical component according to claim 9, The above-mentioned rear cover has a concave portion that faces the above-mentioned end face and holds the above-mentioned end face.

12. The optical component according to claim 9, The surface of the above-mentioned upper surface cover, the above-mentioned lower surface cover, and the above-mentioned rear cover that is adjacent to the surface facing the above-mentioned light guide and is closer to the above-mentioned light-emitting surface side than the above-mentioned reflection surface is set as the light-emitting side surface, The end portions of the above-mentioned light-emitting side surfaces of the above-mentioned upper surface cover, the above-mentioned lower surface cover, and the above-mentioned rear cover are in a curved shape without corners.

13. The optical component according to claim 4, For the above-mentioned light guide, there are protruding rib-shaped protrusions near the above-mentioned upper surface and the above-mentioned lower surface of the above-mentioned reflection surface.

Images